- The Roman crane usually consisted of a drum rotated by a windlass which pulled a rope through several pulleys.
- In Roman Architecture cranes were used to lift heavy weights on Roman construction sites.
Crane Types
- Trispastos
- A single-beam jib, a winch, a rope and a block with 3 pulleys
- Mechanical advantage of 3:1. One man could probably raise 150 kgs (50 kg load x 3)
- Pentaspastos
- Same, but using 2 by 3 pulleys.
- One man could probably raise 450 kgs (3 x 5 x 50 kgs)
- Polyspastos
- Using a set of 3 by 5 pulleys, operated by 4 men, using 2, 3 or 4 masts.
- One man could probably raise 750 kgs (3 ropes x 5 pulleys x 4 men x 50 kgs = 3000 kgs)
- Treadwheel
- If the Winch was replaced with a treadwheel which had a much bigger diameter, the Mechanical advantage would be quadrupled.
- The Load lifted would double to 6,000 kgs for half the manpower, needing only 2 men.
- One man could probably lift 3,000 kgs.
Very Heavy Stone Blocks
- However even bigger stones were lifted by the Roman Engineers.
- 63.3 tons
- Trajan's Column in Rome. The Capital Block weighing 63.3 tons had to be lifted 111 ft (34m) above ground.
- 100 tons
- Baalbeck Roman Temples in Lebanon. Here, they raised the Lintels of 60 tons and one corner block weighing 100 tons, all to a height of 62 ft (19m) above ground.
- 230 tons
- Lateran Obelisk which decorated the Spina of the Circus Maximus in Rome. Originally from the Temple of Amun at Karnak, Egypt, it was brought to Rome by Constantius II in 357 CE. It weighs over 230 tons.
Vitruvius
- Marcus Vitruvius Pollio (c.88-c.26 BCE) was a Roman Engineer who described in ten books called De Architectura, how the Romans built their Aqueducts and other Great Works including a description of the machines that built them. In book I he described Roman town planning.
- This knowledge was lost until he was rediscovered during the Renaissance.
Trajan’s Column